1. Field of the Invention
The present invention relates to a motor and a disk drive apparatus.
2. Description of the Related Art
Conventionally, a disk drive apparatus such as a hard disk drive apparatus or the like is equipped with a spindle motor for rotating a disk. The disk drive apparatus includes a disk, a housing, a stator, a FPC (Flexible Printed Circuit), and so forth. The housing includes a cover member, a base member, and so forth.
In recent years, the disk drive apparatus is required to become smaller in height and size. Particularly, for the sake of further reducing the height of a 2.5 inch-type 7 mm-thick disk drive apparatus which belongs to small-size disk drive apparatuses, it is necessary to reduce the thickness of a motor arranged within the housing. In general, the motor includes a hub, a coil, a stator core, a wiring substrate, a base member, etc. When assembling the motor, these components are arranged to axially overlap with one another. In order for the motor to become thin, these components need to be made thinner. However, if an attempt is made to reduce the overall height of the motor by reducing the turn number of the coils or the lamination thickness of the stator core, the magnetic fluxes generated from the stator during the operation of the motor gets reduced. In other words, a torque constant is reduced. This makes it impossible to obtain the torque required in rotating the disk attached to the hub.
In order to reduce the height of the motor, it is therefore necessary to reduce the thickness of the base member, among the components of the motor, which occupies a large proportion in the axial dimension of the motor. However, if the base member is merely made thin, the rigidity of the base member is reduced to a great extent. As a result, the base member is apt to undergo deformation when a bushing is arranged on the base member.
Accordingly, a demand has existed for a structure capable of fixing a bushing to a base member while reducing the overall height of a motor.